Slide shoe bearings having cardanic supports are often used with tube mills disposed within a slide ring of the bearing. The cardanic supports are usually supported on rollers so as to permit displacement of the slide shoe in the direction of the axis of the mill. In this fashion, the slide shoes can follow movements of the slide ring in that direction, regardless whether such movements result from heat expansion of the mill or from the nonperpendicularity of the plane of the slide rings to the axis of rotation.
The slide ring, the slide shoes, and their supports are encased by a housing encircling the mill which has a short length in its axial direction since the housing is only slightly broader than the slide shoes. The housing is equipped with service hatches through which various kinds of mounting and service operations may be carried out, e.g., mounting of hoses and tubes for pressure lubricated slide shoes.
Sometimes it may be necessary to demount the slide shoe proper, e.g., when recasting a damaged bearing. Since this service is rather rare manufacturers until now have taken no steps to simplify its performance. In each instance, it has been necessary to use whatever means are available on the job which the engineers believe most appropriate.
The most common way of demounting the slide shoe has been to lift the mill sufficiently so that the ball section of the slide shoe is clear of the ball socket bearing. Then by means of a crane or similar device, the slide shoe is pulled up along the slide ring and out through the service hatch in the side of the housing. Such an operation involves great risk of damaging both the slide shoe and the elements meshing with it, e.g. the ball socket bearing. After servicing, the slide shoe, which often weighs more than a ton, is returned to its place by introducing it through the service hatch and lowering it down along the slide ring. A common feature of such replacements is that the operation has been extremely time-consuming.